It is proposed to develop new procedures for the isolation of plasma proteins, in general, using non-denaturing techniques. The key feature of the isolation scheme involves the use of Cibacron Blue Sepharose to bind albumin, while other plasma proteins are resolved into discrete fractions based on their affinity for the gel matrix. It is also proposed to isolate and study the function of two important plasma proteinase inhibitors, not examined in detail before this. These are the inter-alpha-trypsin inhibitor and the alpha-2-thiol proteinase inhibitor. Both of these proteins may be involved in the control of proteolysis by enzymes which could potentially degrade structural proteins leading to the development of emphysema, muscular dystrophy, and other debilitating diseases.